Preventing trees from falling is important to protect human life and property in urban areas. Most trees in urban areas require regular maintenance. To reach upper parts of a tree to perform such maintenance, workers need to climb the tree. However, tree climbing is dangerous, and thus a tree-climbing robot is developed to assist or replace tree climbers in their work.
Several robots have been designed to climb trees. WOODY2006 as proposed by Y. Kushihashi, et al. in “Development of Tree Climbing and Pruning Robot, Woody-1-Simplification of Control using adjust Function of Grasping Power” is a climbing robot designed to replace human workers in removing branches from trees. The robot climbs by encircling the entire tree trunk. The size of the robot is thus proportional to the circumference of the trunk. WOODY2006 avoids branches by turning its body and opening the gripper, but it requires an almost straight tree trunk.
Kawasaki 2008 as proposed by H. Kawasaki, et al., “Novel climbing method of pruning robot” also developed a climbing robot for tree pruning. It uses a gripping mechanism inspired by lumberjacks, and uses a wheel-based driving system for vertical climbing. It encircles the entire tree trunk for fastening on a tree. It cannot avoid branches when the fastening mechanism cannot be opened.